A/C Pressure sensor voltage reading
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1st Gear
Joined: Jul 2025
Posts: 1
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A/C Pressure sensor voltage reading
On a 1995 with the c60 AC system, I am tracing a Clutch will not activate. No control signal on pin D8 on the PCM, I have B1 is low ( AC Request) , D12 3.05 volts( Refrigerant pressure ), B21 low. The Question is on the pressure sensor, with high side reading 100 PSI, what should you the voltage reading be. Question two, where is the module programmed to shut off the AC unit. Again this is the 3 wire sensor, not the low pressure SWITCH. I am thinking that this is a 0 to 5 volt sensor and we are more than mid range on the sensor that I have a bad sensor However, I would still expect that the unit would still be in the operational range for the compressor just above mid range. Guessing the the total range would be something, like .2 volts to 4.8. Now for the last question, anyone know the logic inside of the PCM ? am I missing something?
Melting Slicks
Joined: Feb 2003
Posts: 2,667
Likes: 809
From: Saskatoon Sask.
On a 1995 with the c60 AC system, I am tracing a Clutch will not activate. No control signal on pin D8 on the PCM, I have B1 is low ( AC Request) , D12 3.05 volts( Refrigerant pressure ), B21 low. The Question is on the pressure sensor, with high side reading 100 PSI, what should you the voltage reading be. Question two, where is the module programmed to shut off the AC unit. Again this is the 3 wire sensor, not the low pressure SWITCH. I am thinking that this is a 0 to 5 volt sensor and we are more than mid range on the sensor that I have a bad sensor However, I would still expect that the unit would still be in the operational range for the compressor just above mid range. Guessing the the total range would be something, like .2 volts to 4.8. Now for the last question, anyone know the logic inside of the PCM ? am I missing something?
Last edited by arbee; Jul 5, 2025 at 10:12 AM.
